Low-grade metamorphism in granitoids and volcanic rocks, Cordillera Neuquina, Argentina

Granitoid and volcanic rocks of the Cordillera Neuquina between 38°45′ and 39°30′ south latitude have been metamorphosed under zeolite, prehnite-pumpellyite, and transitional greenschist facies conditions. This low-grade metamorphism is related to the circulation of hydrothermal solutions associated...

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Autores principales: Vattuone de Ponti, M.E., Latorre, C.O.
Formato: JOUR
Materias:
granitoid
greenschist facies
metamorphism
prehnite
pumpellyite
volcanic rock
zeolite
Argentina, Cordillera Neuquina
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_08959811_v3_n4_p247_VattuonedePonti
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_08959811_v3_n4_p247_VattuonedePonti2023-10-03T15:43:06Z Low-grade metamorphism in granitoids and volcanic rocks, Cordillera Neuquina, Argentina Vattuone de Ponti, M.E. Latorre, C.O. granitoid greenschist facies metamorphism prehnite pumpellyite volcanic rock zeolite Argentina, Cordillera Neuquina Granitoid and volcanic rocks of the Cordillera Neuquina between 38°45′ and 39°30′ south latitude have been metamorphosed under zeolite, prehnite-pumpellyite, and transitional greenschist facies conditions. This low-grade metamorphism is related to the circulation of hydrothermal solutions associated with Tertiary(?) subvolcanic bodies and/or shallow intrusives through a pre-existing fracture system. Three progressive metamorphic zones have been established, with temperatures ranging from 100° to 300°C and pressures less than 4 kb. The pressures are similar to those estimated for metamorphic rocks at Taringatura, New Zealand, and in the Tanzawa Mountains of Japan. The mineral assemblages are influenced by host-rock composition. In the granitoids, the sequence is: Zone I - heulandite, stilbite, K-feldspar, albite, quartz, calcite; Zone II - chlorite, prehnite, pumpellyite, albite, K-feldspar, titanite, quartz; and Zone III - chlorite, pistacite, piedmontite, titanite, actinolite, K-feldspar, albite, quartz, calcite. In the basalts, the sequence is: Zone I - heulandite, stilbite, calcite; Zone II - analcime, thomsonite, laumontite, natrolite, celadonite, albite; and Zone III - chlorite, pistacite, actinolite, pumpellyite, laumontite, albite, quartz. In the andesites, the sequence is: Zone I - stilbite, calcite, quartz; Zone II - pumpellyite, chlorite, titanite, celadonite, albite, quartz, calcite; and in Zone III - pistacite, quartz, chlorite, albite. Pyrite, chalcopyrite, arsenopyrite, and copper are always found in association with quartz and epidote in Zone III. © 1991. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_08959811_v3_n4_p247_VattuonedePonti
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic granitoid
greenschist facies
metamorphism
prehnite
pumpellyite
volcanic rock
zeolite
Argentina, Cordillera Neuquina
spellingShingle granitoid
greenschist facies
metamorphism
prehnite
pumpellyite
volcanic rock
zeolite
Argentina, Cordillera Neuquina
Vattuone de Ponti, M.E.
Latorre, C.O.
Low-grade metamorphism in granitoids and volcanic rocks, Cordillera Neuquina, Argentina
topic_facet granitoid
greenschist facies
metamorphism
prehnite
pumpellyite
volcanic rock
zeolite
Argentina, Cordillera Neuquina
description Granitoid and volcanic rocks of the Cordillera Neuquina between 38°45′ and 39°30′ south latitude have been metamorphosed under zeolite, prehnite-pumpellyite, and transitional greenschist facies conditions. This low-grade metamorphism is related to the circulation of hydrothermal solutions associated with Tertiary(?) subvolcanic bodies and/or shallow intrusives through a pre-existing fracture system. Three progressive metamorphic zones have been established, with temperatures ranging from 100° to 300°C and pressures less than 4 kb. The pressures are similar to those estimated for metamorphic rocks at Taringatura, New Zealand, and in the Tanzawa Mountains of Japan. The mineral assemblages are influenced by host-rock composition. In the granitoids, the sequence is: Zone I - heulandite, stilbite, K-feldspar, albite, quartz, calcite; Zone II - chlorite, prehnite, pumpellyite, albite, K-feldspar, titanite, quartz; and Zone III - chlorite, pistacite, piedmontite, titanite, actinolite, K-feldspar, albite, quartz, calcite. In the basalts, the sequence is: Zone I - heulandite, stilbite, calcite; Zone II - analcime, thomsonite, laumontite, natrolite, celadonite, albite; and Zone III - chlorite, pistacite, actinolite, pumpellyite, laumontite, albite, quartz. In the andesites, the sequence is: Zone I - stilbite, calcite, quartz; Zone II - pumpellyite, chlorite, titanite, celadonite, albite, quartz, calcite; and in Zone III - pistacite, quartz, chlorite, albite. Pyrite, chalcopyrite, arsenopyrite, and copper are always found in association with quartz and epidote in Zone III. © 1991.
format JOUR
author Vattuone de Ponti, M.E.
Latorre, C.O.
author_facet Vattuone de Ponti, M.E.
Latorre, C.O.
author_sort Vattuone de Ponti, M.E.
title Low-grade metamorphism in granitoids and volcanic rocks, Cordillera Neuquina, Argentina
title_short Low-grade metamorphism in granitoids and volcanic rocks, Cordillera Neuquina, Argentina
title_full Low-grade metamorphism in granitoids and volcanic rocks, Cordillera Neuquina, Argentina
title_fullStr Low-grade metamorphism in granitoids and volcanic rocks, Cordillera Neuquina, Argentina
title_full_unstemmed Low-grade metamorphism in granitoids and volcanic rocks, Cordillera Neuquina, Argentina
title_sort low-grade metamorphism in granitoids and volcanic rocks, cordillera neuquina, argentina
url http://hdl.handle.net/20.500.12110/paper_08959811_v3_n4_p247_VattuonedePonti
work_keys_str_mv AT vattuonedepontime lowgrademetamorphismingranitoidsandvolcanicrockscordilleraneuquinaargentina
AT latorreco lowgrademetamorphismingranitoidsandvolcanicrockscordilleraneuquinaargentina
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